formalformal

Formal comes from Old French formel, from Latin fōrmālis, from fōrma ‘form’, whose origin is unknown.

1. Latinc. 75 BCE–200 CEfōrma¹‘form’
2. Latinc. 75 BCE–200 CEfōrmālis¹‘formal, of form’
3. Old Frenchc. 842–1400formel¹‘formal’
4. Middle Englishc. 1150–1500formel¹
5. Englishearliest quotation 1965formal¹

1. ¹ Wiktionary, English formal
2. Earliest quotation in Wiktionary’s entry: 1965, Shadow Morton, Sophisticated Boom Boom: “Well, I open up the door / And much…”.